The present invention relates to liquid handling systems, and in particular to a configurable allergen handling system.
Automated assay devices such as immunoassay instruments provide multiple reagent containers for executing a plurality of individual assays. Storage space for each reagent container has become a significant aspect of instrument design in that more than one reagent is typically required for each assay. Further, the desire to automate dictates that such instruments operate with minimal operator intervention, thus emphasizing the need for adequate quantities of reagent in each container.
Any solid phase reagent, and in particular one including paramagnetic particles, requires physical agitation for uniform suspension in a liquid medium. Further, other materials such as incompatible liquids (e.g. oil and water) require similar agitation for homogenous distribution. Existing means for accomplishing this agitation include axial rotation of cylindrical containers having mixing fins therein. However, such mechanisms are necessarily complex to implement, difficult to maintain, and each require significant physical space. Further, such containers are not accessible during instrument operation. Seals for such containers are typically provided as a xe2x80x9cstar capxe2x80x9d, or resilient cap having star-shaped slits. Such caps provide an insufficient barrier to long-term evaporation and to spillage when the container is tipped.
In general, the most significant requirements for individual reagent containers and for housings holding such containers include the following. Each container should include multiple compartments such that all reagents required for a single assay are accommodated. A sufficient quantity of reagent(s) should be accommodated within each reagent container for unattended execution of a series of tests, such as 50 to 250 assays, or more. The containers should be arranged within the housing for simple removal and installation, even during instrument operation. Evaporation and spillage of reagents stored within the pack should be avoided by provision of improved sealing means. Finally, efficient and mechanically simple solid particle suspension should be implemented, allowing continued mixing during instrument operation.
In addition, certain classes of assays require specific reagents selected from a substantial universe of reagents. For instance, allergy testing in an automated immunoassay instrument requires a significant number of specific allergens chosen from among an even larger number representing all possible allergens. Thus, a need exists for providing an automated assay device with a large number of reagents in various combinations, depending upon the assays to be run, and with information as to where each desired reagent is located for automated aspiration within the device. Given a large number of reagents, it is necessary for the device to have a simple but comprehensive capability for learning how the selected reagents are configured for proper aspiration within the device.
The presently disclosed invention provides all the required reagents for multiple iterations of a single assay within minimal space, yet enables mechanically simple and complete admixture of solid reagents within a carrier. Each reagent pack is fully accessible during instrument operation, provided only that reagents from the desired pack are not currently being aspirated or are about to be so aspirated. A pierceable seal in each of multiple reagent pack lid apertures prevents reagent spillage during pack mishandling, minimizes reagent evaporation, and prolongs reagent efficacy. Pack refrigeration further prolongs reagent efficacy.
The present invention provides a reagent pack having at least one chamber for containing all reagents required for a single assay. In a first embodiment, at least one chamber has offset baffles extending from chamber side walls toward the opposing side wall, providing converging and diverging ductwork. The ductwork forms a narrow throat interconnecting two sub-chambers. Suspended reagent or other reactive material flows through this throat region at an accelerated velocity during reagent pack inclination, resulting in agitation and homogenous reagent suspension within each sub-chamber. A continuous lid, sealable to an upper edge of the pack, provides access to underlying chambers via respective apertures in the lid. The reagent pack is disposed on a reagent enclosure tray, and is urged into and out of the enclosure by a respective slide. Provision is made for disposition of multiple packs in a side by side relationship within the enclosure. Inclination of the packs for proper reagent mixing is provided by a motor which periodically tilts the tray back and forth about a central axis.
The reagent packs are accessible to users once a handling system door is lowered. In this position, a number of optical annunciators each corresponding to a respective reagent pack and slide indicate whether the reagent pack is available for manual removal and perhaps replacement. Tray inclination is inhibited during such access. Efficacy of reagents within the enclosure is prolonged by cooling means such as thermal electric devices and heat sinks disposed proximate the enclosure.
A further aspect of the present invention provides a vial carrier having plural reagent compartments disposed linearly along the length of the carrier. Each compartment is adapted for receiving one of plural reagent vials. The carrier is provided with indicia, such as a bar-code, uniquely identifying it to an automated assay device such as an immunoassay instrument. Similarly, each compartment of the carrier has associated with it indicia which are at least unique to the particular carrier. Lastly, each vial installable within a carrier compartment has indicia unique to the contents of the vial. In a further embodiment, the vial indicia are unique to both the vial contents as well as the capacity of the vial.
Vials in the presently disclosed invention are preferentially provided in plural capacities, depending upon the frequency with which reagent contained therein is likely to be utilized within the automated immunoassay instrument. The vials also preferentially employ an integrated cap/seal assembly to minimize evaporation after initial aspiration from the vial. In a further embodiment, a film seal is applied to the vial opening prior to the cap/seal assembly for the purpose of ensuring that the assembly is liquid-tight during handling, shipping and storage, prior to first use within the automated instrument.
In one embodiment of the present invention, the carrier is configured to be disposed on the reagent enclosure tray described above, and is urged into and out of the enclosure by a respective slide, such as the slides described above with respect to the reagent packs. As with the reagent packs, the presently disclosed carriers may be disposed in side by side relationship within the enclosure of the automated instrument. Tray inclination and environment control are also provided in one embodiment, as previously described.
Data reflecting which specific vial is located in which compartment of a given carrier is collected and provided to the automated instrument prior to installation of the carrier into the enclosure. This can be done directly, for instance through the use of a bar-code scanner associated with the instrument, by sequentially detecting: first compartment indicia, indicia associated with the vial installed in the first compartment, second compartment indicia, indicia associated with the vial installed in the second compartment, etc., until all of the compartments and associated vials have been scanned, then scanning indicia identifying the carrier. Intelligence can also be provided to the instrument such that compartments and respective vials are properly identified regardless of scanning order. Alternatively, this data can be gathered manually and entered into the automated instrument via an interface such as a keyboard or touch sensitive display screen. Once the carrier-specific vial information has been provided to the automated instrument, the carrier is then ready for installation. The automated instrument has, associated with the enclosure, means for recognizing and interpreting the indicia provided on each installed carrier. In this manner, the instrument has information reflecting that a desired vial is installed in a particular compartment of a carrier which is installed on a particular slide within the enclosure.
Enhanced configurability for a system requiring a large subset of individually packaged reagents from among a significant universe of such reagents is thus enabled. At the same time, a high degree of reagent density is provided, enabling the maximization of the number of reagents accessible within an automated immunoassay instrument at any one time.